Long-term, Google doesn’t view Chrome just as a browser… they see it as a platform. That’s why they’ve turned Chrome into an operating system. That’s why they opened the Chrome App Store. That’s why they extended Chrome notifications to the desktop. And that’s why they’re now allowing Chrome extensions to run in the background without the browser even being open.

It’s pretty neat functionality, even though there are a minimum of extensions that actually take advantage of the functionality yet. Basically, what you get to do now is start a process and then close all your Chrome windows. Afterwards, the process will stay open in your System Tray (or in OS X’s dock), so it will still keep pumping desktop notifications through to you even if you don’t have any windows open. You can even access your background-enabled extensions from the system tray or dock.

This might seem rather superfluous, but it’s just another step as Google starts treating snippets of browser code as not just extensions, but apps. The new feature comes with some interesting new possibilities, too: for example, extensions can update themselves now, even if Chrome itself isn’t open. That has a lot of potential: Google Voice, for example, can now ring your computer even when your browser’s not open without the installation of a third-party app, while Gmail can slurp down your email.

Right now, as we said, there’s not a lot developers are doing with this… but give it time. For right now, the only real extension to play with is the Countdown timer app, which will send you notifications even when Chrome is closed. I imagine we’ll see much more interesting uses of the tech soon enough, though.